Ball sizing machine



July 27, 1965 G. A. GAZAN BALL SIZING MACHINE 2 Sheets-Sheet 1 FiledMarch 7, 1962 y 7, 1965 G. A. GAZAN 3,196,653

BALL SIZING MACHINE Filed March 7, 1962 2 Sheets-Sheet 2 INVENTOR.G'dkGE A. 6424 ATTOIE'IVI/ United States Patent 3,196,653 BALL SIZINGMACHINE George Anthony Gazan, 22050 Telegraph Road, Southfield, Mich.Filed Mar. 7, 1962, Ser. No. 178,099 2 Claims. (Cl. 7275) This inventionrelates to a machine for ball sizing cylindrical holes and moreparticularly to production apparatus which will allow a plurality ofworkpieces to be sized rapidly, using a single ball repetitively.

The technique of forming a cylindrical hole to an exact diameter, byfirst forming an undersized hole and then forcing through the hole aprecision hardened ball having a diameter greater than the initiallyformed hole, is well known. By exerting forces on the sides of the holein excess of the elastic limit of the hole material, the ball enlargesthe hole. The accuracy of the process is largely dependent upon theprecision to which the ball is formed and its ability to retain itsinitial shape, and to avoid deformation while being forced through anundersized hole. For the later reason, it is essential that the ball bevery hard relative to the material that is to be worked upon.

Previous hole sizing machines for use in production work have commonlyemployed a first reservoir of balls which may be singly fed to apressing apparatus operative to force a ball through a hole to be sized.Another reservoir retained the balls after they were passed through thehole. Periodically, the contents of the returned ball reservoir would betransferred to the first reservoir. Because a plurality of balls wereutilized in such a process, an economic limit was placed upon the costof each ball, and therefore upon the accuracy and hardness of each ball.Additionally, since the balls were stored in contact with one another,both before and after the pressing operation, the surface finish of theballs would become marred.

It is a primary object of the present invention to provide a productionhole sizing machine, employing a single ball which is returned to aninitial position along a soft track under the force of fluid ormechanical pressure after being passed through a hole. The use of a softtrack and fluid or mechanical pressure both insure the retention of theinitial surface finish on the ball and provide a controlled atmosphereas an environment for the ball.

A preferred embodiment of the present invention, which will subsequentlybe described in detail, takes the form of a C-fran1e of a relativelysoft plastic and metal material, having a cylindrical channel slightlygreater than the diameter of the ball to be utilized, passing from oneopposed edge of the frame, around the frame to the opposite opposededge. The frame is normally disposed in a vertical position but can beused horizontally. A springloaded ball retention mechanism is associatedwith the upper end of the track and operates to support a ball above aworkpiece disposed in the gap of the frame. A powered ram is attached tothe frame on its upper side. On proper actuation, it forces the ballthrough the spring-loaded retaining mechanism and through an undersizedhole in a properly positioned workpiece. After passing through the hole,the ball is dropped into the lower leg of the track, and gravity carriesit to the tracks lower extremity. A fluid conduit (in the preferredembodiment the fluid is air) is disposed in an extension of this lowertrack extremity. After the ball has settled in the lower track are-a,valve means inject air into the track at the ball in such a direction asto force the ball up the vertical leg of the track and across theforward leg so that it settles in the springloaded ball retainingmechanism. The apparatus is then in position for operation on the nexthole.

Other objects, advantages and applications of the pres- "ice entinvention will be made apparent by the following detailed description ofa preferred embodiment of the invention. The description makes referenceto the accompanying drawings in which:

FIG. 1 is a perspective view of the preferred embodiment of the presentinvention;

FIG. 2 is an elevation sectional view of the track portion of thepreferred embodiment;

FIG. 3 is a cross sectional view of the track portion of the preferredembodiment taken along lines 3-3 of FIG.

FIG. 4 is a cross section of the track portion taken along lines 44 ofFIG. 3; and

FIG. 5 is a detailed view of the spring-loaded ball retaining mechanism,partly broken away, taken along lines 55 of FIG. 3.

The apparatus may be effectively utilized in connection with a C-framepress generally indicated at 10. The press has a horizontal base section12 which supports the ball sizing apparatus and an overhanging ramsupport section 14. A fluid cylinder 16 is supported from the overheadsection 14 and has a pair of connecting tubes 18 which deliver andreturn fluid under the control of normal valve mechanism (not shown) atan appropriate point in the operational cycle of the device. Motion of apiston within the cylinder 16 causes the extension or retraction of adownward depending rod 20.

A work support fixture 22 is disposed upon the base 12. A handwheelactuated screw 24 passes through the wall of the fixture 22 and locksthe ball track fixture with respect to the base 12. A table 26 dovetailswith the fixture 22 which allows it to be adjusted horizontally andlocked in any position by a set screw 28 for the purpose ofaccommodating various size workpieces.

On its upper surface, the table 26 contains a slide 36 which may bemoved horizontally along the table limited only by the presence of aforward stop 32 and a similar rear stop which is not shown. A V-shapedwork retainer 34 is adjustably supported on the slide 30 by means ofslots 36 and a set screw 38. A workpiece 4%), shown to be a cylindricalcollar having a central hole, may be positioned with respect to theoperating mechanism by placing it in the apex of the V of the workretainer 34 and moving the slide 30 back against the rear stop.

The ball track mechanism generally indicated at 42 comprises a C-framepreferably formed of a rigid yet relatively soft plastic or metalmaterial. Although harder metal tracks will function, they are generallyless desirable.

The track 42 is formed of a first plastic or metal block 44 having asemi-cylindrical groove 46 formed in one of its surfaces. The groove 46extends continuously from a ball input section 48 which terminates atthe upper edge of the lower leg of the C to a ball output section 59located in the upper leg of the track mechanism 42. A flat plastic plate52 attaches to one side of the block 44 so as to completely enclose thegroove 46. The cover 52 is removably attached to the block 44 by aplurality of screws 54. Adjacent the forward edge of the lowermostsection of the groove 46, a fluid passage 56 connects to the outerforward face of the block 44. A threaded coupling 58 allows the passage56 to be coupled to an air line 60.

A spring-loaded ball retaining mechanism connects to the forward upperend of the track mechanism 42 and receives balls from the output section50 of the groove. It comprises a cylindrical collar 62 which has aflange 64 in its lower end which abuts the lower edge of the upper armof the mechanism 42. At its upper end, the collar 62 is inwardly flangedas at 66 to provide a slidable bushing for the cylinder rod 20.

The lower flange 64 carries three inwardly directed,

equi-distant spaced ball retaining probes 68. The probes 68 are biasedin an outer direction by loading springs 70 which are retained withinhollow set screws '72. The set screws thread within the flange 64 sothat rotation of them adjusts the radially inward extension of theprobes 68. The position of the probes is adjusted so that they retain aball 74 which is dropped on top of them from the output in 50 of theball groove 46. Yet,'when the ball 74 is' pressed by the cylinder rod20, the probes 68 retract and allow the ball to pass downwardly. Theexact position of the collar 62 may be adjusted by a pair of screws '76which pass horizontally through the side of the mechanism 42.

In operation, a workpiece having a pro-formed hole with a diameterslightly less than the desired finished diameter is loaded into themachine by inserting in the apex of the V of the work retainer 34 andsliding the work retainer back against the rear stop of the fixture. Atthis point, the ball 74 is supported directly above the upper end of thehole in the workpiece on the ends of the probes 68. The fluid cylinder16 is then actuated so as to cause it to extend its rod 20 which isnormally disposed with its end just within the bushing 66. The downwardmotion of the rod forces the ball 74 against the probes 68 so that theyretract against their loading springs '70 and allow the ball to bepressed through the undersized hole of the workpiece.

After passing through the workpiece, the ball moves through the inputsection 48 of the groove 46. The groove has sufiicient clearance toallow the ball to freely roll to its lowest point. After the ball 74 hassettled there, air is admitted through the passage 56 directly againstthe ball.

The force exerted by the air on the ball causes it to move up throughthe groove 46 across the top leg of the groove and to settle against theupper edges of the probes 68.

The device is at this point ready for another cycle and the ball haspassed through the operational cycle without contacting anything otherthan the soft surface of the groove, the rod 2th of the cylinder (whichmay be tipped with a soft material) and the workpiece.

Having thus described my invention, I claim:

1. A ball sizing machine, comprising: a C-shaped frame member disposedin a vertical position and having a central, generally circular trackextending through the frame and terminating at each extremity thereof;spring retaining means associated with the frame at the upper extremitythereof and operative to receive balls expelled from the upper end ofthe track and to retain such balls, said ball retention means beingspring loaded so that downward force exerted on a ball disposed thereinis operative to release the ball from the retention means; ram meanscooperative with said ball retention means and operative to press a ballthrough said retention means, through an undersized hole in a workpiecedisposed in the gap of the frame, into the lower extremity of saidtrack; a fluid passage associated with the lowest point on said trackoperative to permit entrance of fluid into said track; an a ball havinga diameter substantially equal to the desired diameter of said holenormally disposed within said track.

2. A machine for ball sizing holes, comprising: a C- shaped framemember; a substantially circular groove disposed Within said framemember and terminating adjacent the opposed ends of the C; a ballretaining mechanism asociated with the upper leg of the frame andoperative to receive balls passing through the upper termination of thesaid groove; a ball having a diameter substantially equal to the desireddiameter of said holes normally disposed within said groove, press meansoperatively connected to said ball retention mechanism in such a manneras to force a ball retained within said mechanism through an undersizedhole in a workpiece disposed within a gap in said C in such a mannerthat the ball is returned to the lower terminus of the groove and fallsto the lowermost section of the groove; and an air passage through theframe connecting to said groove adjacent to the lowermost sectionthereof and operative to permit the injection of air at such time as theball is suspended at the lowermost point in the groove so as to returnthe ball through the groove to the ball retention mechanism.

References Cited by the Examiner UNITED STATES PATENTS 906,495 12/ 08Hock 29-90 1,360,55 8 11/20 Mattison 299O 720,375 7/29 Parker 20542,790,500. 4/57 Jones 221 310 CHARLES W. LANHAM, Primary Examiner.

RICHARD H. EANES, WILLIAM J. STEPHENSON,

Examiners.

1. A BALL SIZING MACHINE, COMPRISING: A C-SHAPED FRAME MEMBER DISPOSEDIN A VERTICAL POSITION AND HAVING A CENTRAL, GENERALLY CIRCULAR TRACKEXTENDING THROUGH THE FRAME AND TERMINATING AT EACH EXTREMITY THEREOF;SPRING RETAINING MEANS ASSOCIATED WITH THE FRAME AT THE UPPER EXTREMITYTHEREOF AND OPERATIVE TO RECEIVE BALLS EXPELLED FROM THE SUPPER END OFTHE TRACK AND TO RETAIN SUCH BALLS, SAID BALL RETENTION MEANS BEINGSPRING LOADED SO THAT DOWNWARD FORCE EXERTED ON A BALL DISPOSED THEREINIS OPERATIVE TO RELEASE THE BALL FROM THE RETENTION MEANS; RAM MEANSCOOPERATIVE WITH SAID BALL RETENTION MEANS AND OPERATIVE TO PRESS A BALLTHROUGH SAID RETENTION MEANS, THROUGH AN UNDERSIZED HOLE IN A WORKPIECEDISPOSED IN THE GAP OF THE FRAME, INTO THE LOWER EXTREMITY OF SAIDTRACK; A FLUID PASSAGE ASSOCIATED WITH THE LOWEST POINT ON SAID TRACKOPERATIVE TO PERMIT ENTRANCE OF FLUID INTO SAID TRACK; AN A BALL HAVINGA DIAMETER SUBSTANTIALLY EQUAL TO THE DESIRED DIAMETER OF SAID HOLENORMALLY DISPOSED WITHIN SAID TRACK.